Tensioner mechanism for a portable movie screen



y 11, 1965 E- J. PETRICK 3,182,714

TENSIONER MECHANISM FOR A PORTABLE MOVIE SCREEN Filed April 24, 1963 2Sheets-Sheet 1 Eda/4rd ri e/rick TENSIONER MECHANISM FOR A PORTABLEMOVIE SCREEN Filed April 24, 1965 E. J. PETRICK May 11, 1965 2Sheets-Sheet 2 United States Patent r 3,182,714 TENsIoNEn Mechanism sonA ronranrn Movie scream A Edward J. Patrick, Park Ridge, 121., assignorto Knox Manufacturing Company, a corporation of Illinois Filed Apr. 24,1%3, Ser. No. 275,388 6 Claims. ((11. 160-24) This invention relates toportable projection screens, and more particularly to a tensioningapparatus for stretching the screen fabric taut when in viewingpositions from a screen surface when in viewing position. A

planarscreen surface is important because it eliminates image distortionin the reflected light so that sharply defined objects may be seen onthe screen.

The primary object of the present invention is to provide a new andimproved structure for tensioning a movie screen fabric in open viewingposition.

Another object is to provide a new and improved tensioning device andscreen casing mounting positioned and arranged to mutually cooperate toapply stretching forces to the screen fabric when in viewing position.

A further object is to provide an improved mounting for a screen casingwhich mounting is constructed for limited sliding movement vertically onthe standard.

Still another object is to provide a tensioning device for a screenfabric supported at its opposite marginal edge portions by a pair of rodmembers on an upright support, the tensioning device being in the formof a rotatable cam which upon rotation causes one of the rod members tobe moved away from the other rod member to stretch the screen fabrictaut. 1

The invention is illustrated in a preferred embodiment in theaccompanying drawings, in which:

FIG. 1 is a broken fragmentary side elevational view of a movie screendevice with the screen fabric in exposed tensioned position;

FIG. 2 is a rear elevational view taken from the right of FIG. 1 andshowing the cam turned to its operative position for imparting tensionto the screen fabric;

FIG. 3 is an enlarged fragmentary side elevational view, partly insection, showing the handle, screen casing, and tensioning device ofFIG. 1;

FIG. 4 is a sectional view taken as indicated on line 4-4 of FIG. 3 andshowing the cam and its lever arm turned to tensioning position;

FIG. 5 is a sectional view similar to FIG. 4, but showing the cam andits lever arm turned substantially 90 to nontensioning position; and

FIG. 6 is a fragmentary sectional view taken on line 66 of FIG. 3. r

In the embodiment illustrated, and referring particularly to FIGS. 1 and2, a supporting standard, generally designated 10, is held in uprightposition by a tripod leg unit (not shown). The standard 10 includes atelescoping rod 11 which is sliclably received within a tubular member12, and the rod 11 may be held in varying positions of extendedadjustment by a conventional clamp member 13. The free end of thetelescoping rod is offset rearwardly, as at 14, and is provided with abail support 15 having a number of hook members 16.

A flexible movie screen fabric 17 is conventionally attached at one endto a spring-Wound rod or roller 19 (shown in dotted outline in FIG. 3)which is journaled within an elongated screen casing 18. The fabric 17extends through a longitudinal slot 211 in the casing 18 and is normallyurged to be wound about the roller within the casing 18. It is preferredthat the roller is provided with a roller lock of Well-knownconstruction so that the rotation of the roller is automaticallyarrested when a predetermined length of screen fabric 17 is Withdrawnfrom the casing.

The free end of the screen fabric 17 is secured to a rod member 21 whichmounts a resiliently deformable tension bar 22 secured thereto at 23 and24. The tension bar 22 carries a saddle member 25 to which a bail member26 is swingably secured so that the free end of the screen fabric 17 canbe supported from any one of the several hook members 16 as shown inFIG. 1. The screen structure thus far described is conventional andwell-known in the art. 1

The means for effecting the new and improved tensioning includes a novelmounting between the casing 18 and a handle or support member, generallydesignated 27, to afford relative vertical movement, and a tensioningmeans, generally designated 28, coacting with said mounting to move thecasing 18 and its internal rod or roller 19 away from the rod member 21.

' To this end, the handle member 27 is provided with a hollow chamber 30and upper and lower bearing portions 31 and 32 which make a closeslidable embrace about the tubular member 14. The handle member 27 canbe held in varying positions of vertical adjustment by a slidable bolt34 which in normally urged to its projected position within apreselected one of a number of apertures 35 in the backside of thetubular member 12. Bolt 34 is retracted by depressing button 33.

The forward face of the handle member 27 provides a mounting surface inthe form of a shallow channel which affords a retaining track 36 formounting the screen casing 18 for limited slidable movementlongitudinally of the standard 10. The track 36 is provided with a pairof inwardly projecting shoulders 37 which are spaced from and overlieopposite marginal portions of the track to afford a pair of grooves 38.

The screen casing 18 is provided with structure which fits within thetrack 36 for sliding movement and also is provided with other structureafiording pivotal movement to the casing 18. To this end, the screencasing 18 is provided with an L-shaped bracket 40 secured thereto. Thecasing 18 may be pivoted with respect to a cup shaped support 41 about apivot pin 42 which projects through the rear wall of the casing 18, onearm of the bracket 41) and the bottom of the cup-shaped support 41. Theforward face of the side walls of the cupshaped member 41 affords aperipheral bearing surface 43 to stabilize the casing 18 during itspivotal movement between an inoperative position parallel to the standard 10 and an operative position perpendicular to the standard 10, asshown in FIG. 2.

The bottom of the cup-shaped member 41 is in turn rigidly secured byrivets 44 to an elongated metal slide member 45 which fits within thetrack 36 in the grooves 38. Aspacer 46 may be provided between theopposed faces of the slide 45 and the bottom of the cup-shaped support41 to space the support 41 from the shoulders 37 on the forward face ofthe handle member 27, the width of the spacer 46 permitting it to liebetween the shoulders 37. Aligned apertures 47 and 48 in the spacer 46and the slide 45, respectively, are provided for access to the pivot pin42 for assembly purposes.

Since the slide 45 is freely slidaole within the track 36, a stop 50 isturned inwardly on the upper end of the slide 45 to abut the upper faceof the handle member 27 to limit downward movement of the slide 45together with the casing 18 which is secured thereto as above described.

arr-52x14- 3 The tensioning means 2% is operatively associated with theslide 45 and the handle member 27 so as to cause movement of the casing18 downwardly to stretch the screen material 17 taut in viewingposition.

The tensioner means 28 is pivotally secured to the lower end of theslide 45, as at 51, and preferably includes 2.

- head portion 52 which is peripherally shaped to provide an arcuatecarnming edge 53 and straight edges 55 and 56. A lever arm 54 may beformed integrally with the head portion 52 for manually swinging thetensioner means 28 between an inoperative position (shown in PEG. and anoperative position (shown in FIGS. 2 and 4). As best seen in FIG. 3, itwill be noted that upward movement of the slide 45 is limited by thehead portion 52 abutting the under surface of the handle member 27 (seeFIG. 5), while downward movement of the slide 45 is limited by the bentend portion or stop St? as previously described.

To place the projection screen in viewing position, casing 13 is firstswung to horizontal position, as shown in 15168. 1 and 2. The screenfabric 17 is then pulled outwardly of the casing and suspended from oneof the hook members 16 of the bail support by the bail member 26. Whenthe screen fabric 17 is pulled to exposed position in this manner, theslide also is pulled upwardly in its track 36 to its extreme upwardposition, as shown in FlG. 5. Further upward movement of the slide 45and of the casing 18 mounted thereon is prevented by the edge abuttingagainst the underside of the forward part of the handle member 27 aspreviously explained. At this time,

the lever arm 54 is in its inoperative position (FIG. 5).

The lever arm 54 of the tensioner means 28 is then swungcounterclockwise from its inoperative position (FIG. 5), to itsoperative position (FIG. 4) so that the --arcuate camming edge 53 bearsagainst the underside of the handle member 27 to force the slide 45downwardly in its track 36. The head portion 52 is shaped so that theswinging movement of the lever arm 54 to operative position is slightlygreater than 90 in which position a second'straight edge portion 56engages the underside of the handle member 27, as shown in FIG. 4, toretain the tensioner means 28 in its operative, tensioning position.

Thus, it is apparent that the downward movement of the slide 45 carriesthe casing 18 and its internally journaled reel 1% straight downwardlyof the standard to stretch the screen fabric 17 between the rod or reel19 and t e suspended rod member 21. The movement of the reel 19 awayfrom the rod member 21 also resiliently flexes the tension bar 22 so asto distribute stretching forces in the opposite marginal edge portionsof the screen fabric 17 in a well-known manner,

To release the tension in the screen fabric, it is merely necessary toswing the arm 54 clockwise from the position shown in FIG. 4 to theposition shown in FIG. 5. This releases the forces exerted on thetension bar 22 and in the screen fabric 17 so that the casing 18 and theslide 45are permitted to ride upwardly in the track 36; that is, thereel 19 is caused to move upwardly toward the rod member 21.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom for some modifications will be obvious to those skilled in theart.

I claim: a

1. A portable projection screen, comprising: an upright standard; anelongated hollow screen casing; a flexible screen provided with a pairof rod members one secured to each of the opposite end portions of saidscreen, one rod member being in the form of a spring-wound reel mjournaled in the casing about which the screen is wound in retractedposition, and the otherrod member being adapted to be attached to thestandard to expose the screen in viewing position; a support memberattached to the standard and having a track on its forward face; a slidesecured centrally of the casing and shaped to'cooperate with said trackto permit iimited slidable movement of the casing when the screen is inviewing position; and a cam member on the slide and rotatably mountedfor turning between a tensioning and a nontensioning position, the cammember being positioned and shaped to bear against the support memberwhereby rotation of the cam member to tensioning position moves theslide and casing with respect to the support member to stretch thescreen taut between the rod members.

2. A portable projection screen as specified in claim 1, in which a stopis provided to limit the movement of the slide and casing by the cammember when the cam member is turned to tensioning position.

3. A portable projection screen as specified in claim 1, in which thecam member has a flattened portion on its periphery which bears againstthe support member when the cam member is turned to tensi-oning positionthereby to retain said cam member in said tensioning position.

4. A portable projection screen as specified in claim 1, in which a stopis provided to limit the-slidable movement of the slide and casing inone direction, and the cam member is positioned on the slide to abut thesupport member and limit the slidable movement of the slide and casingin the other direction.

5. A portable projection screen as specified in claim 1, in which thecam member is provided with a lever arm positioned adjacent the standardwhen the cam member is in nontensioning position, said cam member beingpositioned and shaped so that swinging of the lever arm throughsubstantially places the cam member in tensioning position.

6. A portable projection screen, comprising: an upright standard; anelongated hollow screen casing; a flexible screen provided with a pairof rod members one secured to each of-the opposite end portions of saidscreen, one rod member being in the form of a spring wound reeljournaled in the casing about which the screen is wound in retractedposition, and the other rod member being adapted to be attached to thestandard to expose the screen in viewing position; a support memberattached to the standard and having a track on its forward face; 'aslide secured centrally of the casing and cooperating with said track topermit limited slidable movement with the casing when the screen is inviewing position; a rotatable cam memher; and a pair of portions one onthe slide and the other on the standard, one of the portions rotatablymounting the cam member whereby rotation of the cam member causes thecam member to engage the other of the portions to force the slide andthe portion thereon to move away from the other rod member when thescreen is in viewing position to stretch the screen taut between the rodmembers.

References Cited by the Examiner UNITED STATES PATENTS 2,793,687 5/57Petrick 24 FOREIGN PATENTS 444,278 5/27 Germany.

HARRISON R. MOSELEY, Primary Examiner.

6. A PORTABLE PROJECTION SCREEN, COMPRISING: AN UPRIGHT STANDARD; ANELONGATED HOLLOW SCREEN CASING; A FLEXIBLE SCREEN PROVIDED WITH A PAIROF ROD MEMBERS ONE SECURED TO EACH OF THE OPPOSITE END PORTIONS OF SAIDSCREEN, ONE ROD MEMBER BEING IN TH FORM OF A SPRING WOUND REEL JOURNALEDIN THE CASING ABOUT WHICH THE SCREEN IS WOUND IN RETRACTED POSITION, ANDTHE OTHER ROD MEMBER BEING ADAPTED TO BE ATTACHED TO THE STANDARD TOEXPOSE THE SCREEN IN VIEWING POSITION; A SUPPORT MEMBER ATTACHED TO THESTANDARD AND HAVING A TRACK ON ITS FORWARD FACE; A SLIDE SECUREDCENTRALLY OF THE CASING AND COOPERATING WITH SAID TRACK TO PERMITLIMITED SLIDABLE MOVEMENT WITH THE CASING WHEN THE SCREEN IS IN VIEWINGPOSITION; A ROTATABLE CAM MEMBER; AND A PAIR OF PORTIONS ONE ON THESLIDE AND THE OTHER ON THE STANDARD, ONE OF THE PORTIONS ROTATABLYMOUNTING THE CAM MEMBER WHEREBY ROTATION OF THE CAM MEMBER CAUSES THECAM MEMBER TO ENGAGE THE OTHER OF THE PORTIONS TO FORCE THE SLIDE ANDTHE PORTION THEREON TO MOVE AWAY FROM THE OTHER ROD MEMBER WHEN THESCREEN IS IN VIEWING POSITION TO STRETCH THE SCREEN TAUT BETWEEN THE RODMEMBERS.